Multi-stage neutralization of sulfated compounds

Abstract

This invention relates to a process for the multi-stage neutralization of sulfated compounds, particularly sulfuric acids obtained by sulfating alcohols.

What I claim is: 
     
       1. A process for neutralizing a sulfated compound, comprising feeding decreasing quantities of the compound to be neutralized to at least two successive reactors in parallel, feeding to the first reactor substantially the entire quantity of neutralizing agent necessary and sufficient to neutralize the compound, and feeding the output of each reactor to the next reactor in series. 
     
     
       2. A process as claimed in claim 1, in which a proportion of the output of the first reactor is recycled continuously to the first reactor in a quantity of about 5 to 30 times greater than the input to the first reactor. 
     
     
       3. A process as claimed in claim 2, in which heat exchange is performed during recycling. 
     
     
       4. A process as claimed in any of claims 1 to 3, including measuring the pH of the output from the last reactor, and feeding neutralizing agent to the last reactor as a function of the measured pH. 
     
     
       5. A process as claimed in claim 1, using two reactors, in which about 95 to 85% of the sulfated compound is fed to the first reactor and about 5 to 15% to the second reactor, a proportion of the output of the first reactor is recycled continuously to the first reactor in a quantity of about 10 to 20 times the input to the first reactor, the pH of the output from the second reactor is measured, and neutralizing agent is fed to the second reactor as a function of the measured pH. 
     
     
       6. A process according to claim 1 in which said sulfated compound is a monoester of sulfuric acid derived from the sulfation of a sulfatable alcohol. 
     
     
       7. A process for neutralizing a monoester of sulfuric acid derived from the sulfation of a sulfatable alcohol, comprising feeding in parallel quantities of said monoester of sulfuric acid to two successive reactors, feeding to the first reactor substantially the entire quantity of neutralizing agent necessary and sufficient to neutralize said monoester of sulfuric acid and feeding the output of the first reactor to the second reactor, wherein about 95 to 85% of the said monoester of sulfuric acid is fed to the first reactor and about 5 to 15% to the second reactor, a proportion of the output of the first reactor is recycled continuously to said first reactor in a quantity about 10 to 20 times the input to said first reactor, wherein the pH of the output from the second reactor is measured, and neutralizing agent is fed to the second reactor as a function of the measured pH. 
     
     
       8. A process according to claim 6 or 7, wherein said sulfated alcohol is a synthetic alcohol of 12-15 carbon atoms containing three moles of ethylene oxide.